Radiotelegraphy signaling system



H. F. ELLIOTT RADIO TELEGRAPHY SIGNALING SYSTEM Mays, 1923. 1,454,629

Filed June 6, 1921 m- .5. z- T J. WITNESS 4 4 .ATTORNEYS' INVENTOR Patented May S, 1923.

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HAROLD F. ELLIOTT, F PALO ALTO, CALIFORNIA, ASSIGNOR T0 AUGUSTUS TAYLOR,

OE SAN FRANCISCO, CALIFORNIA.

RADIOTELEGRAPHY Application filed June 6,

To aZZ whom it may 0071 06m Be it known that I, HAROLD F. ELLIOTT, a citizen of the United States, and a resident of Palo Alto, Santa Clara County, State of California, have invented certain new and useful Improvements in Radiotelegraphy Signaling Systems, of which the following is a specification. An object of the invention is to provide an efiicient uniwave sig- 10 naling system for radio transmitting stations..

The invention possesses other advantageous features, some of which, with the fore going, will be set forth at length in the following description, where I shall outline in full, that form of the invention which I have selected for illustration in the draw ings accompanying and forming part of the present specification.

In said drawings:

Figure 1 is a diagrammatic representation of a uniwave signaling system embodying my invention.

Fig. 2 is a diagrammatic representation of one of the elements of the system.

Fig. 3 is a diagrammatic representation of a more preferable form of the element shown in Fig. 2.

The system in general comprises an are or other source of continuous oscillations, an antenna circuit connected to the arcfand a local oscillatory circuit connected to the arc. The antenna and local circuits contain inductance and capacity and signaling means are provided for varying the electrical constants of one or both circuits, so that the arc may be causd to oscillate on one circuit to the practical neglect of the other. In practice it is found that one pair of key contacts will handle only a certain amount of current and voltage without undue sparking and wearing, so that in high power stations, the use of a single pair of key contacts is not successful. In accordance with my invention I have provided a signaling means comprising a multiple number of pairsof contacts so arranged that the load on each pair of contacts remains substantially the same, Whether all of the palrs operate simultaneously or successively, thus causing each pair of contacts to handle only a small amount of current and voltage.

The uniwave continuous oscillation trans mission system shown in the accompanying drawingsv comprises an are 2, preferably of SIGNALING sYsrErcc;

1921. Serial No. 475,192.

the Poulsen type, supplied withcurrent from a suitable generator 3 and subjected to a strong transverse magnetic field produced by the electromagnets a. One side of the arc is grounded and the antenna circuit 5'is connected to the other side. Arranged in the antenna circuit is a variable inductor or loadingcoil 6. Connected around the are 13 a local oscillatory circuit 7 containing the variable inductor 8, the variable cap-acitance 9 and the. variable resistor 12. The antenna and local circuits are also preferably coupled by an oscillation transformer 11 of variable coupling. The local circuit may or may not have slightly different electrical characteristics than the antenna circuit. By varying the constants of one or both of the ascillation circuits, the arc may be made to oscillate upon one circuit or the other.

Inductively coupled to the inductors 6 and 8 are loop circuits 13 and 14, which are opened and closed to vary the electrical constants of the antenna and local circuits. The loop is preferably of substantially the same diameter as the associated inductor coil and is arranged concentrically with respect to the coil. In high power stations, the loop voltage is too great to be controlled by a single pair of contacts, and the present invention contemplates controlling the current and voltage with a plurality of pairs of contacts. The loop circuit is divided into a plurality of segments 15, preferably of equal length, by radial conductors 16 connectedat one end tothe loop at equally spaced points and connected together at the other ends, thus dividing the circle of the loop into a plurality of equal sectors. Arranged in each segment is a relay key 17 and a resistor 18,

I one contact of each relay key to earth. .The

relay keys of each loop circuit are simultaneously operated by solenoids or other devices,

so that all or. the contacts of one loop may be substantially simultaneously opened and closed. The signaling key is connected to both relay operating circuits, so that when the signaling key is depressed, one loop circuit is closed and the other opened and vice versa when the signaling key is opened. A purely diagrammatic showing of such control is present in Fig. 1, Where a coil 23 represents the relays operating all of the con tacts 17 for the antenna circuit, and a coil 24 represents similarly the relays operating all of the contacts tor'the local osci. ation circuit. Depression of key 25 Will cause the energization of coil 24, and the release of the key causes a spring 26 to pull the key so as to cause energization of the other coil 23.

The successful operation or this type of signaling system requires that the reactance of the short circuited sector circuit be maintained at a minimum, and I accomplisl this in the arrangement shown in Fig. 3, wherein the reactance in all leads and connections is reduced to a minimum. In this arrangement the relay keys 1'? and resistors 18 are arranged in pairs. One c ntact of each relay key is grounded by the radial conductors 21, connected together at the center of the loop and grounded at that point. The intermediate radial conductors 22, connected together at the center with the conductors :21, serve to equalize the voltage on the relay keys and also carry to earth whatever charging current may be induced on the lrey system, by reason of its proximity to the high voltage parts or the main loading inductor. This disposal of the charging currents is an important feature in the construction of signaling systems of this type, since if not disposed of, the charging currents cause additional sparking at the key contacts. The advantage of the arrangement shown in Fig. 3 over that shown in Fig. 2 is the reduction in the number of leads to the relay keys and consequently a reduction in the reactance of the short circuited loop Which is produced when the keys are closed. The relay keys are operated simultaneously by solenoids or other means as has been hereinhefore set forth.

In practice, it is frequently possible to use only one larger resistor located at one key and omit the small resistors at the individual keys. This simplifies the mechanical construction without seriously unbalancing the division at tli load between the individual keys and also reduces the reactance of the loop.

I claim:

1. A radio telegraphy transmission system including an oscillatory circuit, an inductance coil in said circuit, a plurality of sector circuits inductively connected to said inductance coil, means for discharging the nee recs charging current induced in said sector circuits and means for opening and closing the sector circuits.

2. A radio telegraphytransmission system including an oscillatory circuit, an inductance coil in s; 'd circuit, a loop inductively associated with said coil, a plurality of interconnected conductors connected to the loop at spaced points and dividing the loop into :1 plurality segments, means for discharging the charging current induced in said loop and means in each segment for opening and clos the circuit in each segment.

3. A ra no telegraphy signaling system including an oscillatory circuit, an inductance coil in said circuit, a loop inductively connected to said coil, a plurality of radially disposed conductors interconnected at the center of the loop and connected to the loop at spaced points and dividing the loop into a plurality of segments, a conductor eonne ting the point of interconnection of said conductors to earth and means for opening and closin the circuit in each segment.

l. A radio telegraphy signaling system including an oscillatory circuit, an inductance coil in said circuit, a loop inductively connected to said coil, plurality of resistors arranged in pairs in series in said loop, radial conductors connected to the loop intermediate'the resistors of each pair and interconnected at the center of the loop, switches interposed between each resistor and the radial conductor, and radial conductors connected to the loop between the adjacent resistors of each adjacent pair and connected to the point of interconnection of said first named radial conductors.

5. A radio telegraphy signaling system including an oscillatory circuit, an inductance coil in said circuit, a loop inductively connected to said coil, a plurality of resistors arranged in pairs in series in said loop, radial conductors connected to the loop intermediate the resistors of each pair and inter COllllGCLGCl at the center of the loop, switches interposed between each resistor and the radial conductor, and radial conductors connected to the loop between the adjacent pairs connected to the point of interconnection of said first named radial conductors and a conductor connecting the point of interconnection to earth.

6. A radio telegraphy signaling system comprising a source of radio oscillations, an antenna circuit connected to said source, a local oscillatory circuit connected to said source, a plurality of sector circuits inductively connected to one of said circuits and means for opening and closing the sector circuits to vary the electrical constants of the inductively connected circuit.

T. A radio telegraphy signaling system comprising a source of radio oscillations, an antenna circuit connected to said source, a

local oscillatory circuit connected to said source, a loop inductively coupled to one of said circuits, radial conductors connected to the loop at spaced points, and means for opening and closing the loop.

8. In a radio transmission system, an oscillatory transmission circuit, a signaling circuit coupled to the transmission circuit, and means for discharging the charging current in the signaling circuit due to the proximity of the two circuits.

9. A radio telegraphy signaling system comprising a source oi radio oscillations, an antenna'circuit connected to said source, a local oscillatory circuit connected to said source, a loop inductively coupled to one of said circuits, radial conductors connected to the loop at spaced points dividing the loop into a plurality of segments, a key ineach segment and a resistor in the loop.

10. A radio telegraphy signaling system comprising a source of radio oscillations, an antenna circuit connected to said source, a local oscillatory circuit connected to said source, a loop inductively coupled to one of said circuits, interconnected radial conductors connected to the loop at spaced points dividing the loop into a plurality of seg ments, a key in each segment and a resistor in the loop.

11, A radio telegraphy signaling system comprising a source of radio oscillations, an antenna circuit connected to said source, a local oscillatory circuit connected to said source, a loop inductively coupled to one of said circuits, interconnected radial conductors connected to said loop at spaced points dividing the loop into a plurality of segments and formin a plurality of sector circuits, means for discharging the charging current induced in said sector circuits and means for opening and closing the loop.

12. A radio telegraphy signaling system comprising a source of continuous radio oscillations, two oscillatory circuits connected to the source, one of said circuits being the antenna circuit, an inductance coil in each circuit, a plurality of sector circuits inductively connected to each inductance coil and means for opening and closing the sector circuits to vary the electrical constants of the oscillatory circuits.

13. A radio telegraphy signaling system comprising a source of continuous radio 0scillations, two oscillatory circuits connected to the source, one of said circuits being the antenna circuit, an inductance coil in each circuit, a plurality of sector circuits inductively connected to each inductance coil, 7

means for opening and closing the sector circuits to vary the electrical constants of the oscillatory circuits and means for discharging the charging current induced in viding each loop mto a plurality of segments, and means for opening and closing each segment.

15. A radiotelegraphy signaling system comprising a source of continuous radio oscillations, two oscillatory circuits connected to said source, an inductance coil in each circuit, a loop inductively connected with each coil, interconnected radial conductors connected to each loop at spaced points and di viding each loop into a plurality of seg ments, a resistor in each segment and means for opening and closing each segment.

16. In a radio transmission system, an oscillatory transmission circuit, a signaling circuit coupled to the transmission circuit, and a ground connection from the central point of the signaling circuit.

17. In a radio transmission system, an oscillatory transmission circuit, a plurality of conductors substantially equally inductively coupled to the transmission circuit, means for opening and closing the circuits for the conductors, and an earth connection to the conductors, said connection being symmetrical with respect to all the conductors.

In testimony whereof, I have hereunto set my hand.

HAROLD F. ELLIOTT. 

